Caffeine Half-Life Calculator by Omni
This caffeine half life calculator is designed to estimate how long caffeine remains in your system based on its biological half-life.
How long does caffeine take to half-life?
On average, the half-life of caffeine in healthy adults is approximately 5 to 6 hours. This can vary significantly based on individual factors such as age, liver function, medications, and overall health.
The half-life of caffeine refers to the time it takes for the body to metabolize and eliminate half of the caffeine consumed.
For example, let’s say you consume a cup of coffee containing 100mg of caffeine at 8:00 AM. Assuming a 5-hour half-life:
- By 1:00 PM (5 hours later), approximately 50mg of caffeine would remain in your system.
- By 6:00 PM (10 hours later), about 25mg would be left.
- By 11:00 PM (15 hours later), roughly 12.5mg would still be present.
Caffeine Half-Life Conversion Chart
| Time Since Consumption | Percentage of Caffeine Remaining | Amount Remaining (100mg initial dose) |
|---|---|---|
| 0 hours | 100% | 100 mg |
| 5 hours | 50% | 50 mg |
| 10 hours | 25% | 25 mg |
| 15 hours | 12.5% | 12.5 mg |
| 20 hours | 6.25% | 6.25 mg |
| 25 hours | 3.125% | 3.125 mg |
| 30 hours | 1.5625% | 1.5625 mg |
Caffeine Half-Life Formula
The caffeine half-life can be calculated using the following formula:
C(t) = C₀ * (1/2)^(t/t₁/₂)Where:
- C(t) is the amount of caffeine remaining at time t
- C₀ is the initial amount of caffeine consumed
- t is the time elapsed since consumption
- t₁/₂ is the half-life of caffeine (typically 5-6 hours)
Let’s say you consumed 200mg of caffeine and want to know how much remains after 8 hours, assuming a 5-hour half-life:
C(8) = 200 (1/2)^(8/5) C(8) = 200 (1/2)^1.6 C(8) = 200 * 0.3295 C(8) ≈ 65.9 mgAfter 8 hours, approximately 65.9mg of caffeine would remain in your system.
Caffeine Half Life by Age Chart
| Age Group | Average Caffeine Half-Life |
|---|---|
| Newborns | 65-130 hours |
| Infants (3-5 mo) | 14 hours |
| Children (6-13) | 2.3-4.3 hours |
| Adults (18-45) | 5-6 hours |
| Adults (65-70) | 7 hours |
| Pregnant women | 8-10 hours |
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